Carburetor



Oct. 12, 1937. w. B. GOODMAN I 2,095,739

CARBURETOR Filed Jan. 29, 1935 INVENTOR.

illara' B. Goodman Patented Oct.12,1937

UNITED STATES 2,0 5,13 CARBUBETQR.

, I Willard B. Goodman, Paterson, N. 1.; assignor to Wright AeronauticalCorporation, a corporation of New York Application January 29, 1935,Serial No. 3,923 2 Claims. (01. 261-72) This invention relates tocarburetors in general and more specifically to carburetors for highoutput engines, such as used in aircraft.

A prime-object of the invention is to provide an improved and simplemeans for completely shutting off the fuel flow when it is desired tostop the engine, to prevent the after-firing which often occurs, on highoutput engines, after the ignition switch has been out, which firing isdue to hot plug points or carbon particles in the combustion chambers.

Further objects will be apparent from a reading of the subjoinedspecification and claims and from a consideration of the accompanyingdrawing, in which:

Fig. 1 is a diagrammatic axial section through an inverted carburetorincorporating the invention;

Fig. 2 is a plan view of a the-carburetor;

Fig. 3 is a plan view of a disc valve; and

Fig. 4 is a plan view showing the valve in position on the seat.

Referring first to Fig. 1, l0 designates the body valve seat formed inof an inverted carburetor having an air entrance 12, a usual venturi l4,and throttle Hi. The carburetor is bolted to the inlet of the engine(not shown) at the lower face iii. A main discharge" jet is indicated atand a main-air bleed at 22. An idle feed passage is indicated at 24 andan idle metering jet at 26, while an idle air bleed at 28 connects tothe discharge jets 30. A main metering jet is indicated at 32 asdisposed in.a float chamber 34, the latter being provided with a vent 36entering the venturi l4 to balance the chamber pressure with the venturipressure.

The parts so far described represent a conventional carburetorarrangement, and the object of the back suction control of thisinvention, now to be described, is to provide a positive means wherebythe fuel flow can be shut off from all of the various passages describedabove. j

Above the float chamber 34 there is an altitude or mixture control valvewhich normally comprises a rotatable disc 40 having a cut-away portion42 (Fig. 3) by which the opening area at a float chamber vent hole 44may be controlled. 'A fixed seat 46 is provided for this valve, whichhas a stem 48 extending through a cover plate 50 to carry the controllever 52. The elements just describedrepresent a conventional altitudecontrol, but, according to the provisions of thisinvention the followingelements are added.

From the under side of the throttle IS a suction passage 54 is ledaround the float chamber 34 to a hole 56 in the valve seat 46, the seathaving an additional hole 58 (Fig. 2) communicating with the interior ofthe float chamber. In the under-side of the disc valve 40 there is addedan arcuate groove 60 (Figs. 3 and 4) so arranged cations and changes.

that when the valve is moved to the positio shown in Fig. 4 the holes 58and 56 are connected by the groove 60, placing the float chamber incommunication with the under side of the throttle through the passage54. This position of the valve 40 occurs beyond the range of its normalmovement for altitude control so that the altitude control hole 44 iscovered when the extra -movement is utilized to connect the holes 58,56.

This'closed position for the altitude control hole 44 corresponds to thefull-rich condition of that control, which is always in force when theairplane is on the ground. The operation of the device is as follows: i

In order to stop the engine it is first brought to idle by closing thethrottle in the usual way.

which creates a high suction below the throttle valve l6. Then, bymovement of the altitude control lever 52 beyond the normal full-richposition, this suction is communicated to the interior oi the floatchamber through the passage 54, the

holes 56, 58, and the groovefili, as already de- 4 scribed. Thisinstantly draws back into the float chamber all of the fuel in each ofthe various J'et passages, so that no fuel can issue to the inlet airand the engine accordingly immediately stops and the possibility ofafter-firing is eliminated.

While I have described my invention in detail I x in its presentpreferred embodiment, it will be obvious to those skilled in the art,after understanding my invention, that various changes and modificationsmay be made therein without departing from the spirit or scope thereof.I aim in the appended claims to cover all such modifi- What is claimedis:

1. Means to shut off the fuel flow from an engine carburetor having athrottle and a float chamber, comprising a passageway connecting onlythe-engine side of said throttle and said float chamber, means to keepsaid connection normally closed and movable to establish the connectionat will, saidmeans being incorporated injan otherwise conventionalaltitude control valve.

2. The'combination with a carburetor having a throttle, a float chamber,an altitude control valve separately operable from said throttl andpassages connecting the atmosphere wit said float chamber through saidvalve, of passages connecting said float chamber-with/the engine side ofsaid throttle, through said valve, said valve hav--. ing openingsadapted, in difierent positions thereof, to establish communication inone position,

between said chamber and the engine side of said throttle, and, inanother position, to establish communication betweenthe float chamberand the atmosphere.

WRLARD B. GOODMAN.

